1. Field of the Invention
The present invention relates to an analytical method to quickly and automatically separate many kinds of hydrocarbon compounds contained in a solution into three types, namely, saturates, unsaturates and aromatics and analyze them.
2. Description of the Prior Art
The requirement to separate many kinds of hydrocarbon compounds contained in a solution into three groups of saturates, unsaturates and aromatics and analyze them is an immutable one. Recently this requirement becomes increasingly remarkable because the revision of the standards for fuel oils and the like are clamored.
Heretofore, a method, so-called fluorescent indicator adsoption method described in JIS K 2536 or ASTM D 1319 has been carried out for such a requirement; however, from the current practical viewpoint, there are various problems in these methods such as complicated operation and long time required for analysis.
A high speed liquid chromatograhy which has been remarkably developed in recent years is one of the methods to solve these problems. As these analytical methods using high speed chromatography, there has been known the instance wherein n-hexane or a fluorine-containing compound is used; however, this method has some disadvantages such as low solubility and high cost of hydrocarbon compound and complexity of device such as adoption of back flash mode. Further, a problem still remains in the performance of quantitative analysis since a differential refractometer is used in detection part.